diff --git a/libraries/mbed/targets/hal/TARGET_Freescale/TARGET_KLXX/TARGET_KL25Z/PeripheralPins.c b/libraries/mbed/targets/hal/TARGET_Freescale/TARGET_KLXX/TARGET_KL25Z/PeripheralPins.c
index 629fc49828..ef77ff1882 100644
--- a/libraries/mbed/targets/hal/TARGET_Freescale/TARGET_KLXX/TARGET_KL25Z/PeripheralPins.c
+++ b/libraries/mbed/targets/hal/TARGET_Freescale/TARGET_KLXX/TARGET_KL25Z/PeripheralPins.c
@@ -19,7 +19,7 @@
 
 /************RTC***************/
 const PinMap PinMap_RTC[] = {
-    {PTC1, RTC_CLKIN, 2},
+    {PTC1, RTC_CLKIN, 1},
 };
 
 /************ADC***************/
diff --git a/libraries/mbed/targets/hal/TARGET_Freescale/TARGET_KLXX/TARGET_KL46Z/PeripheralPins.c b/libraries/mbed/targets/hal/TARGET_Freescale/TARGET_KLXX/TARGET_KL46Z/PeripheralPins.c
index 37d96d040a..58057d178a 100644
--- a/libraries/mbed/targets/hal/TARGET_Freescale/TARGET_KLXX/TARGET_KL46Z/PeripheralPins.c
+++ b/libraries/mbed/targets/hal/TARGET_Freescale/TARGET_KLXX/TARGET_KL46Z/PeripheralPins.c
@@ -18,7 +18,7 @@
 
 /************RTC***************/
 const PinMap PinMap_RTC[] = {
-    {PTC1, RTC_CLKIN, 2},
+    {PTC1, RTC_CLKIN, 1},
 };
 
 /************ADC***************/
diff --git a/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC176X/serial_api.c b/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC176X/serial_api.c
index 2a06b61c31..d6c60a852b 100644
--- a/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC176X/serial_api.c
+++ b/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC176X/serial_api.c
@@ -364,12 +364,10 @@ int serial_readable(serial_t *obj) {
 }
 
 int serial_writable(serial_t *obj) {
-    int isWritable = 1;
     if (NC != uart_data[obj->index].sw_cts.pin)
-        isWritable = gpio_read(&uart_data[obj->index].sw_cts) == 0;
-    if (isWritable)
-        isWritable = obj->uart->LSR & 0x40;
-    return isWritable;
+        return (gpio_read(&uart_data[obj->index].sw_cts) == 0) && (obj->uart->LSR & 0x40);  //If flow control: writable if CTS low + UART done
+    else
+        return obj->uart->LSR & 0x20;                                                       //No flow control: writable if space in holding register
 }
 
 void serial_clear(serial_t *obj) {